What happens if Boris Johnson resigns or is forced out?

It seems likely, perhaps even inevitable, that Boris Johnson will resign as prime minister or be forced out within days. Here is what could follow.

What happens if Johnson resigns?

There are two options here. One is if Johnson, under pressure from ministers and MPs, agrees to leave No 10 the moment a replacement is found, as happened with Theresa May in 2019. Under this scenario nothing formal would need to happen – Johnson would stay in post, attempt to patch together an interim cabinet, and the focus would shift to choosing his replacement.

If he resigned with immediate effect it would require an interim PM to be appointed, as constitutionally there needs to be a prime minister in post at all times. Dominic Raab, the justice secretary, is the deputy prime minister and would be the default choice, but if he was standing to replace Johnson and it was felt incumbency could give him an unfair advantage, it is possible a more neutral option could step in.

How does a prime minister resign?

In a chronology known very well from TV news helicopter footage, a car takes them to Buckingham Palace, where they tender their resignation to the Queen, who then – on the advice of the ruling party – appoints a new prime minister.

This most usually happens after general elections, although in recent years, Tony Blair, David Cameron and Theresa May have stood down in mid-parliament. All stayed in office until a successor was chosen.

Could Johnson call an election?

Now the fixed-term parliaments act has been repealed, under law an election can be requested by the prime minister at any time – and speaking to the liaison committee of MPs on Wednesday, Johnson hinted he could do this if colleagues try to force him out.

But to seek an election without the blessing of the government or the bulk of your own MPs would be constitutionally very unusual, and would be fiercely resisted. Under a constitutional convention known as the Lascelles principle, a monarch can refuse a request for an election for reasons including if the parliament is still deemed “viable”, if an election could harm the economy, or if a credible alternative PM existed.

It it understood that Buckingham Palace has been taking advice on what to do if Johnson does seek such a snap election.

How would a new prime minister be chosen?

By Conservative MPs and then members – the choice is for a leader of the Tory party, who is then prime minister as the party has a Commons majority.

Under rules set out in 1997, the first stage is – assuming there are more than two candidates – for the hopefuls to be whittled down by a series of votes by Tory MPs.

The precise method for this is set out by the party’s backbench 1922 committee before each race, but in every round of MP voting, the candidate with the least support among MPs, and potentially also those who fail to reach a set threshold of votes, are eliminated, depending on the size of the parliamentary party at the time

The final two are then voted on by party members, a longer process involving a series of hustings events. In 2019, when Johnson replaced Theresa May, the entire leadership process took about six weeks.

The precise method for this is set out by the party’s backbench 1922 committee before each race, but in every round of MP voting, the candidate with the least support among MPs, and potentially also those who fail to reach a set threshold of votes, are eliminated, depending on the size of the parliamentary party at the time.

Johnson is known for his ability to wiggle out of tight spots, managing to remain in power despite suggestions that he was too close to party donors, that he protected supporters from bullying and corruption allegations, and that he misled Parliament about parties in government offices that broke COVID-19 lockdown rules.

He hung on even when 41% of Conservative lawmakers voted to oust him in a no-confidence vote last month and formerly loyal lieutenants urged him to quit.

But recent revelations that Johnson knew about sexual misconduct allegations against a lawmaker before he promoted the man to a senior position in his government have pushed him to the brink.

Many of his fellow Conservatives were concerned that Johnson no longer had the moral authority to govern at a time when difficult decisions are needed to address soaring food and energy prices, rising COVID-19 infections and the war in Ukraine. Others worry that he may now be a liability at the ballot box.

Johnson’s grilling in Parliament was the first of two Wednesday. He was also questioned by a committee of senior lawmakers.

Under current party rules, another no-confidence vote cannot be held for another 11 months, but party members can change that rule.

Months of discontent over Johnson’s judgment and ethics erupted when Javid and Treasury chief Rishi Sunak resigned within minutes of each other on Tuesday evening. The two heavyweights of the Cabinet were responsible for tackling two of the biggest issues facing Britain — the cost-of-living crisis and the COVID-19 pandemic.

In a scathing letter, Sunak said: “The public rightly expect government to be conducted properly, competently and seriously. … I believe these standards are worth fighting for and that is why I am resigning.”

Javid said the party needs “humility, grip and a new direction,” but “it is clear this situation will not change under your leadership.”

Mindful of the need to shore up confidence, Johnson quickly replaced the ministers, promoting Nadhim Zahawi from the education department to treasury chief and installing his chief of staff, Steve Barclay, as health secretary.

But the resignations of more than 30 junior ministers and ministerial aides followed Tuesday and Wednesday.

As Johnson dug in, critics accused him of refusing to accept the inevitable and of behaving more like a president than a prime minister by referring to his “mandate.” In Britain, voters elect a party to govern, not the prime minister directly.

Former International Development Secretary Andrew Mitchell said late Tuesday that Johnson’s time was finally up.

“It’s a bit like the death of Rasputin: He’s been poisoned, stabbed, he’s been shot, his body’s been dumped in a freezing river, and still he lives,’’ Mitchell told the BBC. “But this is an abnormal prime minister, a brilliantly charismatic, very funny, very amusing, big, big character. But I’m afraid he has neither the character nor the temperament to be our prime minister.”

The final straw for Sunak and Javid was the prime minister’s handling of sexual misconduct allegations against Conservative lawmaker Chris Pincher.

Last week, Pincher resigned as deputy chief whip after complaints he groped two men at a private club. That triggered a series of reports about past allegations leveled against Pincher — and shifting explanations from the government about what Johnson knew when he tapped the man for a senior job enforcing party discipline.

It was all too much for ministers who have been sent out to defend the government’s position in radio and TV interviews, only to find the story changed within a few hours.

Bim Afolami, who quit as Conservative Party vice chairman on Tuesday, said he had been willing to give Johnson the benefit of the doubt — until the Pincher affair.

“The difficulty is not overall the program of the government,” he said. “The problem is character and integrity in Downing Street, and I think that people in the Conservative Party and people in the country know that.”

Paul Drechsler, chair of the International Chamber of Commerce in Britain, said change is needed at the top if the government is going to address a growing economic crisis.

“I would say the most important thing to do is to feed people who are hungry,’’ he told the BBC. “The poorest in our society are going to be starving to death the second half of this year. That needs to be addressed.”